variable

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare destructiveHint=true and readOnlyHint=false, so the safety profile is known without the description. The description adds one genuinely useful prerequisite (writes require project= or project_id), but it never says that delete is irreversible, what gets removed, or that list can run without a project. Useful but far from complete for a destructive mutation tool.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two compact sentences, front-loaded with purpose before actions and prerequisites. Minor cosmetic flaw: the action list runs straight into 'Write:' with no separator, making the sentence boundary ambiguous.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

A 10-parameter, destructive, multi-action CRUD tool with no output schema and 20% schema coverage demands far more detail than two sentences. The description omits how each action pairs with the params, what list returns, and the consequences of delete, leaving real gaps for correct invocation.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 20%, so the description must carry the burden for 8 undocumented parameters. Instead it restates what the schema already says: the action enum values and the project requirement (already in the project property description). It leaves name, value, variable_id, is_secret, description, and category semantics unexplained.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Manage project variables') and names the concrete facets (servers, credentials, config) plus the full action set (create, list, update, delete). What it lacks is any differentiation from the many sibling project tools; nothing tells the agent why 'variable' rather than 'rules' or 'log_learning' applies.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The action list and the 'Write: requires project=' prerequisite give implied guidance on how to invoke write operations. But there is no explicit when-to-use / when-not-to-use statement and no routing to alternatives among the 30+ siblings, so the agent must infer the scope.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.